"Having President Poroshenko address Congress is another signal of our steadfast commitment to the aspirations of his people," Boehner said in a statement.
Poroshenko is scheduled to meet President Barack Obama in the White House on the same day. The pair held talks last week on the eve of the NATO summit in Wales where they discussed the conflict between Kiev's US-backed government and pro-Russian separatists in eastern Ukraine.
Ukraine is in upheaval amid the separatist push, although a fragile truce has held over the past week.
The embattled Poroshenko, who became president three months ago in the wake of a revolution that ousted Kremlin-leaning strongman Viktor Yanukovych, said today that Russia had withdrawn most of the troops it allegedly moved across the border to bolster the rebels.
He also vowed greater autonomy for the separatist east in a bid to sustain the shaky ceasefire.
The latest foreign dignitary to address a joint meeting of Congress was South Korea's President Park Geun-Hye, who spoke to members of the House of Representatives and Senate on May 8, 2013.
